A keratoma is a benign mass made up of keratin that is situated between the hoof wall and distal phalanx. The cause is unknown. Although keratomas originate at the level of the coronary band, the condition may be difficult to detect until the growth is well advanced and located in the wall far distal to the coronary band. There is commonly bulging of either the coronary band or the hoof wall over the keratoma, depending on its position within the foot. Pressure from the keratoma causes well-demarcated bone resorption of the distal phalanx (usually appears that a “bite” has been taken out of the solar margin in most cases), which can usually be visualized best via the 65° dorsopalmar radiographic view of the distal phalanx. Surgical removal of the mass is indicated. Once localized, it is best to resect the mass through an approach through the hoof wall versus from a solar approach.
Last full review/revision September 2015 by James K. Belknap, DVM, PhD, DACVS